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Re: [Qemu-devel] [RFC][PATCH 11/15] memory: Allow unaligned address_spac
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [RFC][PATCH 11/15] memory: Allow unaligned address_space_rw |
Date: |
Mon, 06 May 2013 16:55:47 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130311 Thunderbird/17.0.4 |
Il 06/05/2013 16:26, Jan Kiszka ha scritto:
> This will be needed for some corner cases with para-virtual the I/O
> ports.
>
> Signed-off-by: Jan Kiszka <address@hidden>
> ---
> exec.c | 33 ++++++++++++++++++---------------
> 1 files changed, 18 insertions(+), 15 deletions(-)
>
> diff --git a/exec.c b/exec.c
> index 3ee1f3f..9c582b1 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -1833,38 +1833,41 @@ void address_space_rw(AddressSpace *as, hwaddr addr,
> uint8_t *buf,
> uint8_t *ptr;
> uint32_t val;
> MemoryRegionSection *section;
> + MemoryRegion *mr;
>
> while (len > 0) {
> l = ((addr & TARGET_PAGE_MASK) + TARGET_PAGE_SIZE) - addr;
> if (l > len)
> l = len;
> section = address_space_lookup_region(as, addr);
> + mr = section->mr;
>
> if (is_write) {
> - if (!memory_region_is_ram(section->mr)) {
> + if (!memory_region_is_ram(mr)) {
> hwaddr addr1;
> addr1 = memory_region_section_addr(section, addr);
> /* XXX: could force cpu_single_env to NULL to avoid
> potential bugs */
> - if (l >= 4 && ((addr1 & 3) == 0)) {
> + if (l >= 4 && ((addr1 & 3) == 0 || mr->ops->impl.unaligned))
> {
Does the length matter at all if unaligned accesses are allowed? I
think it shouldn't...
Paolo
> /* 32 bit write access */
> val = ldl_p(buf);
> - io_mem_write(section->mr, addr1, val, 4);
> + io_mem_write(mr, addr1, val, 4);
> l = 4;
> - } else if (l >= 2 && ((addr1 & 1) == 0)) {
> + } else if (l >= 2 &&
> + ((addr1 & 1) == 0 || mr->ops->impl.unaligned)) {
> /* 16 bit write access */
> val = lduw_p(buf);
> - io_mem_write(section->mr, addr1, val, 2);
> + io_mem_write(mr, addr1, val, 2);
> l = 2;
> } else {
> /* 8 bit write access */
> val = ldub_p(buf);
> - io_mem_write(section->mr, addr1, val, 1);
> + io_mem_write(mr, addr1, val, 1);
> l = 1;
> }
> } else if (!section->readonly) {
> ram_addr_t addr1;
> - addr1 = memory_region_get_ram_addr(section->mr)
> + addr1 = memory_region_get_ram_addr(mr)
> + memory_region_section_addr(section, addr);
> /* RAM case */
> ptr = qemu_get_ram_ptr(addr1);
> @@ -1873,30 +1876,30 @@ void address_space_rw(AddressSpace *as, hwaddr addr,
> uint8_t *buf,
> qemu_put_ram_ptr(ptr);
> }
> } else {
> - if (!(memory_region_is_ram(section->mr) ||
> - memory_region_is_romd(section->mr))) {
> + if (!(memory_region_is_ram(mr) || memory_region_is_romd(mr))) {
> hwaddr addr1;
> /* I/O case */
> addr1 = memory_region_section_addr(section, addr);
> - if (l >= 4 && ((addr1 & 3) == 0)) {
> + if (l >= 4 && ((addr1 & 3) == 0 || mr->ops->impl.unaligned))
> {
> /* 32 bit read access */
> - val = io_mem_read(section->mr, addr1, 4);
> + val = io_mem_read(mr, addr1, 4);
> stl_p(buf, val);
> l = 4;
> - } else if (l >= 2 && ((addr1 & 1) == 0)) {
> + } else if (l >= 2 &&
> + ((addr1 & 1) == 0 || mr->ops->impl.unaligned)) {
> /* 16 bit read access */
> - val = io_mem_read(section->mr, addr1, 2);
> + val = io_mem_read(mr, addr1, 2);
> stw_p(buf, val);
> l = 2;
> } else {
> /* 8 bit read access */
> - val = io_mem_read(section->mr, addr1, 1);
> + val = io_mem_read(mr, addr1, 1);
> stb_p(buf, val);
> l = 1;
> }
> } else {
> /* RAM case */
> - ptr = qemu_get_ram_ptr(section->mr->ram_addr
> + ptr = qemu_get_ram_ptr(mr->ram_addr
> + memory_region_section_addr(section,
> addr));
> memcpy(buf, ptr, l);
>
- Re: [Qemu-devel] [RFC][PATCH 10/15] memory: Rework sub-page handling, (continued)
[Qemu-devel] [RFC][PATCH 08/15] isa: implement isa_is_ioport_assigned via memory_region_find, Jan Kiszka, 2013/05/06
[Qemu-devel] [RFC][PATCH 11/15] memory: Allow unaligned address_space_rw, Jan Kiszka, 2013/05/06
- Re: [Qemu-devel] [RFC][PATCH 11/15] memory: Allow unaligned address_space_rw,
Paolo Bonzini <=
[Qemu-devel] [RFC][PATCH 09/15] memory: Introduce address_space_lookup_region, Jan Kiszka, 2013/05/06
[Qemu-devel] [RFC][PATCH 07/15] Privatize register_ioport_read/write, Jan Kiszka, 2013/05/06
[Qemu-devel] [RFC][PATCH 01/15] adlib: replace register_ioport*, Jan Kiszka, 2013/05/06
[Qemu-devel] [RFC][PATCH 04/15] i82374: replace register_ioport*, Jan Kiszka, 2013/05/06
[Qemu-devel] [RFC][PATCH 15/15] ioport: Move IOPortRead/WriteFunc typedefs to memory.h, Jan Kiszka, 2013/05/06